Wild salmon populations have declined dramatically across the Northern Hemisphere; habitat protection, barrier removal, and water quality improvement are essential for their welfare and survival.
Wild salmon face a cascade of stressors that compromise welfare and survival across their life cycle. Dams prevent spawning migration, forcing fish to expend massive energy reserves attempting to ascend impassable barriers or divert into tributaries with unsuitable spawning habitat. Water temperature stress during summer migration causes physiological exhaustion, immune compromise, and increased disease susceptibility. Predation pressure near hatchery releases exposes wild stocks to high predator concentrations. Sea lice emanating from salmon farms create infectious burdens that juvenile wild salmon are not adapted to manage. Each stressor compounds the others — addressing habitat connectivity and thermal refugia through dam removal and riparian restoration supports both wild salmon welfare and conservation.